[SPARK-53678][SQL] Fix NPE when subclass of ColumnVector is created with null DataType

Author: manuzhang

sql/catalyst/src/main/java/org/apache/spark/sql/vectorized/ColumnVector.java

@@ -338,7 +338,7 @@ public final VariantVal getVariant(int rowId) {
    * Sets up the data type of this column vector.
    */
   protected ColumnVector(DataType type) {
-    this.type = type.transformRecursively(
+    this.type = type == null ? null : type.transformRecursively(
       new PartialFunction<DataType, DataType>() {
         @Override
         public boolean isDefinedAt(DataType x) {

sql/core/src/test/scala/org/apache/spark/sql/execution/vectorized/ConstantColumnVectorSuite.scala

@@ -204,4 +204,8 @@ class ConstantColumnVectorSuite extends SparkFunSuite {
       assert(vector.getChild(2).getLong(i) == 12345L)
     }
   }
+
+  testVector("null DataType", 0, null) { vector =>
+    assert(vector.dataType == null)
+  }
 }